Reproducibility of bowel ultrasonography in the evaluation of Crohn's disease

Gastrointestinal ultrasound in inflammatory bowel disease: an underused resource with potential paradigm-changing application

Evolution of treatment targets in IBD has increased the need for objective monitoring of disease activity to guide therapeutic strategy. Although mucosal healing is the current target of therapy in IBD, endoscopy is invasive, expensive and unappealing to patients. GI ultrasound (GIUS) represents a non-invasive modality to assess disease activity in IBD. It is accurate, cost-effective and reproducible. GIUS can be performed at the point of care without specific patient preparation so as to facilitate clinical decision-making. As compared with ileocolonoscopy and other imaging modalities (CT and MRI), GIUS is accurate in diagnosing IBD, detecting complications of disease including fistulae, strictures and abscesses, monitoring disease activity and detecting postoperative disease recurrence. International groups increasingly recognise GIUS as a valuable tool with paradigm-changing application in the management of IBD; however, uptake outside parts of continental Europe has been slow and GIUS is underused in many countries. The aim of this review is to present a pragmatic guide to the positioning of GIUS in IBD clinical practice, providing evidence for use, algorithms for integration into practice, training pathways and a strategic implementation framework.

Ultrasonography in Gastroenterology: The Need for Training

The use of ultrasonography (US) as an imaging modality in medicine has spread across almost every clinical specialty. This diffusion is based on the simplicity, accessibility, portability and affordability of the technique producing real-time high-resolution images using non-ionising radiation. On the other hand, this trend also extended the technique to settings other than healthcare, such as public facilities, private houses or remote sites. This tendency can be observed worldwide, from developing countries to prestigious medical schools and tertiary referral hospitals. Furthermore, point-of-care US (POCUS), i.e., US executed at the patient's bedside to obtain real-time objective information with diagnostic and clinical monitoring purposes or to guide invasive procedures, has been incorporated in many specialties. In gastroenterology, despite the essential role of endoscopy, clinical practice is highly dependent on non-endoscopic imaging techniques. However, as in other specialties, the indications of US in gastroenterology have been increasing steadily, covering a broad range of conditions. In response to the generalised employment of US by non-radiologists, institutions such as the European Federation of Societies for Ultrasound in Medicine and Biology and the Royal College of Radiologists issued recommendations to ensure high-quality practice. These theoretical and practical requisites include performing a certain number of examinations and mandatory skills in order to achieve certification to execute unsupervised US. Therefore, there is a need for modern gastroenterology to include US as a basic skill in its clinical practice. To ensure the provision of high-quality US, adequate instruction of future specialists should be guaranteed by the gastroenterology departments and required in the residency training programme.

Ultrasound Elasticity Imaging Predicts Therapeutic Outcomes of Patients With Crohn's Disease Treated With Anti-Tumour Necrosis Factor Antibodies

BACKGROUND AND AIMS

Ultrasound elasticity imaging is a non-invasive technique developed to evaluate fibrosis. Measuring tissue strain by ultrasound elasticity imaging can reliably detect severe ileal fibrosis in patients with Crohn's disease [CD]. We have hypothesised that a more severe range of fibrosis might influence the therapeutic response to anti-tumour necrosis factor [TNF] treatment. The aim of this study was to assess the ability of ultrasound elasticity imaging to predict the therapeutic outcome for CD patients.

METHODS

Consecutive patients with ileal/ileocolonic CD, starting anti-TNF treatment, were enrolled for the study. These patients underwent bowel ultrasound and ultrasound elasticity imaging at baseline and at 14 and 52 weeks after anti-TNF treatment. Bowel wall stiffness was quantified by calculating the strain ratio between the mesenteric tissue and the bowel wall. Strain ratio ≥ 2 was used to identify severe ileal fibrosis. Transmural healing at 14 and 52 weeks was defined as bowel wall thickness ≤ 3 mm.

RESULTS

Thirty patients with CD were enrolled. Five patients underwent surgery for bowel obstruction. The frequency of surgeries was significantly greater in patients with a strain ratio ≥ 2 at baseline [p = 0.003]. A significant reduction of the bowel thickness was observed after 14 and 52 weeks of anti-TNF treatment [p < 0.005]. A significant inverse correlation was observed between the strain ratio values at baseline and the thickness variations following anti-TNF therapy [p = 0.007]; 27% of patients achieved transmural healing at 14 weeks. The baseline strain ratio was significantly lower in patients with transmural healing [p < 0.05].

CONCLUSIONS

This study shows that ultrasound elasticity imaging predicts therapeutic outcomes for CD patients treated with anti-TNF.

Assessment of Crohn's disease activity by Doppler sonography

Objectives:

To investigate the diagnostic accuracy of ultrasound for evaluation of inflammatory activity in patients with Crohn’s disease (CD).

Methods:

Fifty-six patients with histologically proven CD (39 with active, 17 with inactive disease) and 30 healthy volunteers as a control group were enrolled in the study at WeiFang People’s Hospital, Weifang Province, China from October 2012 to December 2014. Bowel wall thickness, and vascularity pattern were measured by Doppler ultrasound.

Results:

There was a significant difference in flow volume of the superior mesenteric artery (585 ± 235 ml/min) in the patients with active disease, compared with those with inactive disease (401 ± 238 ml/min) and the control group (390 ± 189 ml/min, p<0.001). Wall thickness was 5.1 ± 1.5 mm in the active CD group, 3.3 ± 1.6 mm in the inactive disease group (p<0.001) and <3 mm in the control group. Resistance index in the thickened bowel wall showed some differences: 0.68 ± 0.05 in the active disease group, 0.78 ± 0.08 in the inactive disease group, and 0.85 ± 0.07 in the control group (p<0.05).

Conclusion:

Doppler ultrasound is a useful diagnostic tool in detecting CD and assessing inflammatory activity.

Monitoring of small bowel Crohn's disease

In recent years, the therapeutic paradigm in Crohn's disease has shifted from a mere symptom-oriented approach, to aiming to healing of the underlying inflammation and prevention of long-term structural complications. Such 'treat-to-target' approach may allow for a more stable disease course with less hospitalizations, lower requirement for surgery and improved quality of life. In Crohn's disease, the small bowel is affected in the majority of patients; frequently, Crohn's involves only the small bowel, which remains inaccessible to conventional ileocolonoscopic techniques. Thus, non-invasive monitoring techniques are crucial for accurate disease assessment. Areas covered: This review addresses the indications and clinical implications of non-invasive small bowel monitoring modalities (magnetic resonance enterography, intestinal ultrasound, capsule endoscopy) in the assessment and management of Crohn's disease. Expert commentary: This review addresses the limitations of the current knowledge and future areas of research, including the possible utilization of transmural healing as an imaging target and the need to establish clear quantitative target values to guide treatment by imaging findings in Crohn's disease.

Cross-sectional evaluation of transmural healing in patients with Crohn's disease on maintenance treatment with anti-TNF alpha agents

BACKGROUND

Transmural healing (TH) of Crohn's disease (CD) is a still unexplored and interesting outcome correlated to concept of deep remission.

AIM

To assess the rate of TH in CD patients treated with anti-TNF alpha agents using two cross-sectional procedures: bowel sonography (BS) and magnetic resonance enterography (MRE).

METHODS

We performed a 2-year observational longitudinal study, evaluating steroid-free clinical remission (CR), mucosal healing (MH), and TH in CD patients who would complete a 2-year treatment period with anti-TNFs. All patients underwent endoscopy, BS, and MRE before and after 2 years of treatment.

RESULTS

Forty out of 80 CD patients were treated with anti-TNFs for 2 years. CR was achieved in 24 patients (60%) while MH in 14 (35%). Using BS, TH was observed in 10 patients (25%), while using MRE, TH was observed in 9 patients (23%) (k=0.90; P<0.01). A good agreement was observed between MH and TH, both using BS (k=0.63; P<0.01) and MRE (k=0.64; P<0.01). A poor agreement was found between CR and TH, with both BS and MRE (k=0.27 and 0.29, respectively; P<0.01); even though all patients with TH had achieved CR.

CONCLUSIONS

TH can be achieved in about 25% of CD patients treated with anti-TNFs, as shown by BS and MRE. BS could be used as the first cross-sectional procedure to detect TH.

Ultrasound Shear Wave Elastography and Contrast Enhancement: Effective Biomarkers in Crohn's Disease Strictures

BACKGROUND

Inflammation, fibrosis, and muscular hypertrophy lead to thickened bowel in Crohn's disease forming strictures. Ultrasound shear wave elastography (SWE) measures bowel wall stiffness. Contrast-enhanced ultrasound (CEUS) uniquely detects bowel wall inflammation. We aim to correlate SWE of ileal Crohn's disease in vivo to CEUS peak enhancement and pathology grades of inflammation, fibrosis, and muscular hypertrophy.

METHODS

In a prospective institutional review board-approved study, 105 consecutive ileal patients with Crohn's disease received ultrasound. At maximal bowel wall thickness (>4 mm), SWE and CEUS were performed. Fifteen patients had ileal resection within a mean time interval of 71.0 ± 66.9 days. Pathology scores for inflammation, fibrosis, and muscular hypertrophy were compared with SWE and CEUS measurements.

RESULTS

Mean in vivo SWE velocity for patients with and without surgery was 2.8 ± 0.7 and 2.2 ± 0.8 m/s (P < 0.01), respectively. In all ileal specimens, chronic exceeded active inflammatory change (P < 0.001). There was an inverse relationship between CEUS peak enhancement and both fibrosis, r = -0.59, P = 0.02, and SWE velocity measurements, r = -0.61, P = 0.03. Strictured bowel specimens had more smooth muscle hypertrophy than fibrosis, P < 0.001. There was moderate correlation between SWE and muscular hypertrophy, r = 0.59, P = 0.02 and no significant relationship between SWE and fibrosis scores (P > 0.05).

CONCLUSIONS

Stiffer bowel from smooth muscle hypertrophy increases SWE measurements. We report a novel relation of high SWE with muscle hypertrophy, and inverse relationship with CEUS peak enhancement; providing differentiation between active and chronic bowel wall inflammation to improve selection between medical therapy and surgery.

Bowel Damage in Crohn's Disease: Direct Comparison of Ultrasonography-based and Magnetic Resonance-based Lemann Index

BACKGROUND

The Lémann index (LI), calculated by magnetic resonance (MR) or computed tomography enterography in association with endoscopy, was developed to assess bowel damage (BD) in Crohn's disease (CD). Our aim was to investigate the concordance between ultrasonography-based Lèmann index (US-LI) and magnetic resonance-based Lèmann index (MR-LI).

METHODS

We prospectively evaluated all consecutive patients with CD referred to our IBD Unit. All patients had undergone endoscopy, US and MR within 1 month. US-LI and MR-LI were calculated by scoring previous surgery, location, extension, and intestinal complications. Furthermore, we evaluated the association between LI and: CD duration, Harvey-Bradshaw index, and other relevant clinical features. In accordance with recent literature, an LI >4.8 was considered indicative of BD.

RESULTS

Seventy-one patients with CD were examined. About CD location, 36% showed ileal disease (L1), 10% showed colonic CD (L2), whereas 54% had an ileocolonic disease (L3). Moreover, 27% of patients presented a noncomplicated behavior (B1), 45% had almost one stricture (B2), whereas 28% showed penetrating CD (B3). Perianal CD was observed in 16% of subjects, whereas 40% had undergone previous surgery. MR-LI and US-LI were 6.62 (95% confidence interval, 4.2-9.7) and 6.04 (95% confidence interval, 3.6-9.2), respectively (r = 0.90; P < 0.001), with 35 patients (49%) showing an LI indicative of BD. No significant correlation was evident between LI and Harvey-Bradshaw index (P = 0.9), whereas a significant correlation was found between both US-LI/MR-LI and CD duration (P = 0.01).

CONCLUSIONS

US-LI shows high concordance with MR-LI and could be considered a good option for assessing BD in CD by using a highly available and relatively inexpensive procedure.

Bowel Thickening in Crohn's Disease: Fibrosis or Inflammation? Diagnostic Ultrasound Imaging Tools

The high frequency of intestinal strictures in patients with Crohn's disease and the different treatment approaches specific for each type of stenosis make the differentiation between fibrotic and inflammatory strictures crucial in management of the disease. However, there is no standardized approach to evaluate and discriminate intestinal strictures, and until now, there was no established cross-sectional imaging modality to detect fibrosis. New techniques, such as contrast-enhanced ultrasound and sonoelastography allow the assessment of vascularization and mechanical properties of stenotic bowel tissue, respectively. These techniques have shown great potential to characterize strictures in Crohn's disease. The aim of this review is to sum up the current knowledge on bowel ultrasound tools to discriminate inflammatory from fibrotic stenosis in Crohn's disease considering the most recent published studies in the field.

Utility of MR enterography and ultrasound for the investigation of small bowel Crohn's disease

Cross sectional Imaging plays an increasingly important role the diagnosis and management of Crohn's disease. Particular emphasis is placed on MRI and Ultrasound as they do not impart ionising radiation. Both modalities have reported high sensitivity for disease detection, activity assessment and evaluation of extra-luminal complications, and have positive effects on clinical decision making. International Guidelines now recommend MRI and Ultrasound in the routine management of Crohn's disease patients. This article reviews the current evidence base supporting both modalities with an emphasis on the key clinical questions. We describe current protocols, basic imaging findings and highlight areas in need of further research.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 4 J. MAGN. RESON. IMAGING 2017;45:1573-1588.

The use of ultrasound in inflammatory bowel disease

Imaging in inflammatory bowel disease (IBD) plays a pivotal role in the primary diagnosis, as well as during the management of patients with known IBD. The evolution of ultrasound equipment and the growing expertise of examiners have both enhanced the role of intestinal ultrasound in the assessment of the gastrointestinal tract in IBD patients. Intestinal ultrasound has been shown to have high sensitivity and specificity, as well as high positive and negative predictive value, in the detection or exclusion of intestinal inflammatory activity in IBD. The obvious advantages of intestinal ultrasound over other imaging modalities include non-invasiveness, rapid availability and low costs. This review summarizes the current developments in the use of intestinal ultrasound for the detection of IBD and its complications, and discusses its use in the management of patients with IBD. Indications for the use of intestinal ultrasound in daily practice are presented, expanded by new developments such as contrast-enhanced ultrasonography and elastography.

Endoscopy and cross-sectional imaging for assessing Crohn׳s disease activity

Crohn's disease (CD) is principally characterized by chronic and recurrent inflammation of the gastrointestinal tract, most commonly found in the ileo-colonic region. The chronicity and severity of intestinal inflammation together contribute to progressive, cumulative, deep, transmural intestinal damage, including stricturing, obstruction, abscesses, and fistulae. Both intestinal inflammation and its chronic complications result in a range of symptoms subsequently leading to patient presentations with diarrhea, abdominal pain, and anemia related to intestinal blood loss. Measuring disease activity and severity are essential for decision of treatment intensity early in the disease course and longitudinal monitoring of therapeutic efficacy. This review will summarize the transition from subjective symptoms driving disease activity indices, into increasingly objective and quantitative measures of intestinal injury by direct mucosal assessment (endoscopy), cross-sectional imaging, and surrogate biomarkers. Specific commentary on intestinal stricture and perianal fistula assessment and management are presented in accompanying sections of this series.

Medical Imaging in Small Bowel Crohn's Disease-Computer Tomography Enterography, Magnetic Resonance Enterography, and Ultrasound: "Which One Is the Best for What?"

BACKGROUND

Small bowel imaging in Crohn's disease (CD) is an important adjunct to endoscopy for the diagnosis, assessment of postoperative recurrence, and detection of complications. The best imaging modality for such indications though remains unclear. This systematic review aims to identify the imaging modality of choice considering the use of ultrasound (US), computed tomography enterography (CTE), and magnetic resonance enterography (MRE).

METHODS

Databases were systematically searched for studies pertaining to the performance of US, CTE, and MRE, as compared with a predefined reference standard in the assessment of small bowel CD.

RESULTS

Thirty-three studies, from a total of 1427 studies, were included in the final analysis. A comparable performance was demonstrated for MRE, CTE, and US for the diagnosis of small CD. Ultrasound was found to have the highest accuracy in the differentiation of inflammation and fibrosis. Postoperative recurrence detection was feasible with the use of MRE and US. All 3 modalities were shown to have a role in the detection of small bowel CD complications. The radiation exposure associated with CTE can be minimized by using lower radiation protocols.

CONCLUSIONS

Ultrasound, CTE, and MRE all play an important role in the diagnosis and management of small bowel CD, with preference for a particular modality being influenced by specific indication, institution resources, and patient preference.

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts

BACKGROUND

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use.

METHODS

Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English.

RESULTS

The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent.

CONCLUSIONS

Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Quantifying inadvertent thermal bowel injury from the monopolar instrument

BACKGROUND

Insulation defects are observed in 3-39 % of laparoscopic instruments. Electrosurgical injuries due to insulation defects or capacitive coupling remain an issue in laparoscopic surgery with a prevalence of 0.6-5 per thousand cases. Shielded instruments with active electrode monitoring (AEM) have been postulated to prevent these injuries. The benefit of these instruments has not been quantified. Most bowel injuries are unrecognized intra-operatively. Injury is revealed only after the patient exhibits peritonitis symptoms and surgical intervention to repair the bowel is required. These injuries may result in devastating and costly complications or mortality. The extent of bowel injury possible with commonly used generator settings and associated energy output has never been histologically defined. Our objectives in this experimental study were: quantify and compare the energy released through insulation defects or capacitive coupling with standard unshielded monopolar versus shielded instruments with (AEM), determine energy required to cause a visible burn, and relate the histological burn depth to a given amount of energy.

METHODS

Ex vivo porcine jejunum was used for tissue testing. An oscilloscope measured energy output from three common electrosurgical generators at recommended power settings with standard or AEM instruments with insulation defects and in capacitive coupling scenarios. Presence of a visible burn was noted, and depth of tissue damage for a given amount of energy was measured histologically.

RESULTS

All samples that received ≥3.8 J of energy had visible burns. As little as 10 J caused full wall thickness burns. 3.8 J was exceeded at the 30- and 50-W power settings in every experimental scenario using standard monopolar instruments; AEM instruments never approached this much energy.

CONCLUSIONS

Serious burn injury results from small amounts of energy leaked from standard instruments. AEM instruments appeared protective and did not leak sufficient energy to cause burn injuries to the bowel.

Prospective cohort study of ultrasound-ultrasound and ultrasound-MR enterography agreement in the evaluation of pediatric small bowel Crohn disease

BACKGROUND

There is a paucity of published literature describing ultrasound (US)-US and US-MR enterography (MRE) inter-radiologist agreement in pediatric small bowel Crohn disease.

OBJECTIVE

To prospectively assess US-US and US-MRE inter-radiologist agreement in pediatric small bowel Crohn disease.

MATERIALS AND METHODS

Institutional Review Board approval and informed consent/assent were obtained for this HIPAA-compliant prospective cohort study of children with newly diagnosed distal small bowel Crohn disease (July 2012 to December 2014). Enrolled subjects (n = 29) underwent two small bowel US examinations performed by blinded independent radiologists both before and at multiple time points after initiation of medical therapy (231 unique US examinations, in total); 134 US examinations were associated with concurrent MRE. The MRE examination was interpreted by a third blinded radiologist. The following was documented on each examination: involved length of ileum (cm); maximum bowel wall thickness (mm); amount of bowel wall and mesenteric Doppler signal, and presence of stricture, penetrating disease and/or abscess. Inter-radiologist agreement was assessed with single-measure, three-way, mixed-model intra-class correlation coefficients (ICC) and prevalence-adjusted, bias-adjusted kappa statistics (κ). Numbers in brackets are 95% confidence intervals.

RESULTS

Ultrasound-US agreement was moderate for involved length (ICC: 0.41 [0.35-0.49]); substantial for maximum bowel wall thickness (ICC: 0.67 [0.64-0.70]); moderate for bowel wall Doppler signal (ICC: 0.53 [0.48-0.59]); slight for mesenteric Doppler signal (ICC: 0.25 [0.18-0.42]), and moderate to almost perfect for stricture (κ: 0.54), penetrating disease (κ: 0.80), and abscess (κ: 0.96). US-MRE agreement was moderate for involved length (ICC: 0.42 [0.37-0.49]); substantial for maximum bowel wall thickness (ICC: 0.66 [0.65-0.69]), and substantial to almost perfect for stricture (κ: 0.61), penetrating disease (κ: 0.72) and abscess (κ: 0.88).

CONCLUSION

Ultrasound-US agreement was similar to US-MRE agreement for assessing pediatric small bowel Crohn disease. Discrepancies in US-US and US-MRE reporting question the utility of US as an accurate, reproducible radiologic biomarker for assessing response to medical therapy and disease-related complications.

Bowel ultrasound imaging in patients with cystic fibrosis: Relationship with clinical symptoms and CFTR genotype

BACKGROUND

Ultrasound imaging is used to assess bowel abnormalities in gastrointestinal diseases. We aimed to assess the rate of predefined bowel ultrasound signs and their relationship with gastrointestinal symptoms and the cystic fibrosis transmembrane conductance regulator (CFTR) genotype in cystic fibrosis patients in regular follow-up.

METHODS

Prospective study of 70 consecutive patients with cystic fibrosis and 45 controls who underwent abdominal ultrasound; pertinent findings were related to gastrointestinal symptoms and, in cystic fibrosis patients, to pancreatic status, malabsorption degree, lipase intake, CFTR genotype (classified as severe or mild against functional class of CFTR mutations).

RESULTS

96% patients showed at least one abnormal bowel ultrasound sign. Most frequent signs were lymph node enlargement (64%), bowel loop dilatation (55%), thick corpuscular intraluminal content (49%), bowel wall hypervascularization (26%), thickened bowel wall (22%) and intussusception (17%). Patients with recurrent abdominal pain showed more bowel wall hypervascularization than patients without recurrent pain (47% vs. 19%, respectively; p = 0.02) and intussusception (58% vs. 17%, respectively; p < 0.01). Genotype was not associated to specific bowel ultrasound signs. Patients with bowel loop intussusception showed greater lipase intake than those without intussusception (8.118 ± 2.083 vs. 5.994 ± 4.187, respectively; p < 0.01).

CONCLUSION

Cystic fibrosis patients present a higher rate of bowel ultrasound abnormalities than controls. Bowel ultrasound abnormalities are associated with abdominal symptoms.

The Role of Ultrasound Elasticity Imaging in Predicting Ileal Fibrosis in Crohn's Disease Patients

BACKGOUND

Bowel wall fibrosis is associated with a complicated disease behavior in patients with Crohn's disease (CD). The quantitative assessment of fibrosis severity in CD-affected bowel can help clinical decision making. Our aim was to evaluate the feasibility, reliability, and reproducibility of ultrasound elasticity imaging (UEI) toward the assessment of ileal fibrosis in CD patients.

METHODS

Twenty-three consecutive patients with ileal or ileocolonic CD, elected for surgical resection of the terminal ileum, underwent bowel ultrasound and UEI. Twenty inflammatory CD patients without complications were enrolled as controls. Bowel wall stiffness was evaluated with UEI by means of color scale and quantitative strain ratio measurement. The severity of bowel wall fibrosis and inflammation were evaluated on histological sections by semiquantitative and quantitative image analysis and used as a reference standard.

RESULTS

The UEI strain ratio measurement was significantly correlated with the severity of bowel fibrosis at both semiquantitative and quantitative histological image analysis: it was characterized by an excellent discriminatory ability for severe bowel fibrosis (area under the receiver operating characteristic curve: 0.917; 95% confidence interval, 0.788-1.000). UEI strain ratio measurements were characterized by an excellent interrater agreement. At multivariate analysis, bowel wall fibrosis proved the only independent determinant of the strain ratio. The ileal strain ratio of inflammatory CD patients was significantly lower than in operated CD patients with severe fibrosis.

CONCLUSIONS

UEI can be used to assess ileal fibrosis in CD patients.

Use of Imaging Techniques in Inflammatory Bowel Diseases That Minimize Radiation Exposure

The use of imaging in the management of inflammatory bowel disease (IBD) has grown exponentially in the last few years. This has raised concerns about the risk of high cumulative level of radiation exposure from medical imaging in IBD patients during their lifetime, especially when the disease begins in pediatric age. Physicians caring for IBD children should be aware of the malignant potential of ionizing radiation and of the availability of alternative radiation-free techniques such as magnetic resonance imaging (MRI) and ultrasonography (US), in order to use them whenever possible. This review will focus on the value of US and MRI in pediatric IBD.

Failure of gastroenterologists to apply intestinal ultrasound in inflammatory bowel disease in the Asia-Pacific: a need for action

Intestinal ultrasound (IUS) is a cheap, noninvasive, risk-free procedure that is significantly underutilized in the diagnosis and management of patients with inflammatory bowel disease (IBD) in the Asia-Pacific region. More cost-effective methods of monitoring disease activity are required in light of the increasing global burden of IBD (especially in Asia), the advent of personalized medicine, and the rising cost of healthcare. IUS is a prime example of a technique that meets these needs. Its common clinical applications include assessing the activity and complications of IBD. In continental Europe, countries such as Germany and Italy use this imaging tool as the standard of care and have integrated it into management protocols. There are formal training programs in these countries to train gastroenterologists in IUS, and it is used in an outpatient setting during patient consultations. Barriers to its use in the Asia-Pacific region include lack of experience and research data, and there are few established centers with active training programs. These concerns can be addressed by investing more in IUS service provision and by increasing allocation of resources toward local research and training. Increased uptake of IUS will ultimately benefit patients with IBD.

Small intestinal contrast ultrasonography for the detection of small bowel complications in Crohn's disease: correlation with intraoperative findings and magnetic resonance enterography

BACKGROUND AND AIMS

In evaluating small bowel Crohn's disease (CD), small intestine contrast-enhanced ultrasonography (SICUS) is emerging as an alternative to magnetic resonance enterography (MRE). This retrospective study compared the diagnostic accuracy of SICUS and MRE with surgical findings, and their level of agreement.

METHODS

We identified a cohort of CD patients investigated by either SICUS and/or MRE that subsequently required resective bowel surgery within 6 months. The accuracy and agreement of SICUS and MRE to detect small bowel complications were compared with intraoperative findings using kappa coefficient (κ). Agreement between SICUS and MRE in those undergoing both modalities was also assessed.

RESULTS

A total of 67 patients were evaluated; 25 underwent SICUS and 17 underwent MRE prior to surgery. Another 25 patients underwent both SICUS and MRE. When compared with intraoperative findings, the sensitivity of SICUS and MRE was 87.5% and 100%, respectively, in detecting strictures, 87.7% and 66.7% for fistulae, 100% for both in identifying abscesses, 100% and 66.7% for bowel dilatation, and 94.7% and 81.8% in defining bowel wall thickening. When correlating SICUS and MRE with surgery, there was a high level of agreement in localizing strictures (κ = 0.75, 0.88, respectively), fistulae (κ = 0.82, 0.79) and abscesses (κ = 0.87, 0.77). Concordance between SICUS and MRE was substantial or almost complete in identifying stricturing disease (κ = 0.84), their number and location (κ = 0.85), fistulae (κ = 0.65), and mucosal thickening (κ = 0.61).

CONCLUSION

SICUS accurately identified small bowel complications and correlated well with MRE and intraoperative findings. SICUS offers an alternative in the preoperative assessment of CD.

Clinical relevance of patency capsule combined with abdominal ultrasonography to detect small bowel strictures

BACKGROUND

PillCam patency capsule (PC) is a novel and radiofrequency identification tag-free device that remains intact in the gastrointestinal tract for 30-33 h after ingestion and then disintegrates. The aim of this study was to determine the clinical relevance of PC combined with abdominal ultrasonography as a reliable indicator of functional patency.

PATIENTS AND METHODS

The study was prospective and PillCam PC was administered to consecutive patients with known or suspected small bowel strictures. PC was verified if it was excreted intact in 33 h after administration. Following excretion failure and radiograph detection in the pelvic cavity, ultrasonography was used to detect the PC in relation to the stricture.

RESULTS

The participants were 52 patients with known or suspected small bowel strictures (58% women, mean age 51 years, including 32 with or suspected Crohn's disease). Twenty-two patients (42.3%) retrieved PC in the stool within 33 h after ingestion. Radiograph identified the four PCs in the colon and eight were not observed. Ultrasonography precisely judged all 17 PCs retained including six PCs at the proximal side of small bowel stricture in the patients considered ineligible for capsule endoscopy (CE). In all eligible patients, CE passed through the small intestine without incident.

CONCLUSION

PillCam PC combined with ultrasonography before CE appears to be a reliable indicator of functional patency to predict and minimize the risk of impaction in suspected or even known cases with small bowel stricture.

Role of bowel ultrasound in the management of postoperative Crohn's disease

The use of biological and immunosuppressive therapy in Crohn’s disease (CD) changed favorably the course of the disease and is currently suggested in the prevention of clinical recurrence. Symptomatic exacerbation is a feature of the natural course of the disease. Endoscopic recurrence may occur earlier than clinical manifestations and its rate is still high ever since the first year after surgery. The severity of mucosal lesions is highly predictive of a new flare of the disease so that the early detection of recurrence warrants strong therapeutic changes or a closer monitoring of the case. Endoscopy is at present the gold-standard technique for the diagnosis and grading of recurrence severity, but is poorly accepted by patients for its invasiveness. A simple and easy repeatable examination able to detect early signs of recurrence could be useful in the follow-up as an alternative or as a backing in the choice of the right timing for endoscopy in questionable cases. The use of bowel ultrasound (B-US) in the management of CD has grown in the past twenty years. Its accuracy in the real time detection of the disease and its complications, known since the 80’s, together with the non-invasiveness, low cost and wide availability of the technique have influenced the extension of its clinical use in many referral centers in Europe. The latest generation of ultrasound scanners allows a precise and reproducible morphological assessment of the intestinal tract and the surrounding tissues and enables a complete evaluation of the disease. This review analyzes the literature history about B-US in the diagnosis of postoperative recurrence of CD and outlines the clinical implications of its use. Published works confirm a very good accuracy of B-US in the diagnosis of CD recurrence compared to endoscopy, also in the early phase. B-US shows a good correlation with Rutgeert’s score grading, but does not prove significant association with C-reactive protein or CD Activity Index values. A wider use of B-US in the daily practice could allow to set a prompt diagnosis and an earlier and targeted treatment, probably sparing more invasive tests.

Review article: optimal preparation for surgery in Crohn's disease

BACKGROUND

One-third of Crohn's disease (CD) patients will undergo abdominal surgery within the first 5 years of diagnosis.

AIM

To review the available evidence on pre-operative optimisation of CD patients.

METHODS

The literature regarding psychological support, radiological imaging, abdominal abscess management, nutritional support, thromboembolic prophylaxis and immunosuppression in the perioperative setting was reviewed.

RESULTS

For diagnosis of fistulas, abscesses and stenosis, ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) have a high diagnostic accuracy. Under either CT or US guidance, it is possible to perform abscess percutaneous drainage (PD), which, with systemic antibiotic therapy, should be the first-line approach to intra-abdominal abscesses. CD patients with weight loss <10% within the last 3-6 months, body mass index < 18.5 kg/m(2) and/or albumin levels <30 g/L, are at an increased risk of post-operative complications. Pre-operative nutritional support should be used in these patients. IBD patients undergoing surgery have a higher risk of venous thromboembolic disease than patients with colorectal cancer, and current guidelines recommend that they should receive prophylaxis with heparin. Whether the use of anti-TNF agents before surgery increases the likelihood of post-operative complications, is the subject of much debate. To date, cumulative evidence from most studies (all retrospective) suggests that there is no such risk increment. Prospective studies are necessary to firmly establish this conclusion.

CONCLUSIONS

Preparation for surgery requires close interaction between surgeons, gastroenterologist, radiologists, psychologists and the patient. Correct pre-operative planning of surgical treatment has a major impact on the outcome of such treatment.

Ultrasonography of the colon in pediatric ulcerative colitis: a prospective, blind, comparative study with colonoscopy

OBJECTIVES

To evaluate the usefulness of colonic ultrasonography (US) in assessing the extent and activity of disease in pediatric ulcerative colitis (UC) and to compare US findings with clinical and endoscopic features.

STUDY DESIGN

Consecutive pediatric patients (n = 60) with a diagnosis of UC and suspected disease flare-up were prospectively enrolled; of these, 50 patients were eligible for the study. All underwent clinical evaluation, bowel US with color Doppler examination and colonoscopy. Blind US was performed the day before endoscopy in all patients. The US assessed variables were bowel wall thickness >3 mm, bowel wall stratification, vascularity, presence of haustra coli, and enlarged mesenteric lymph nodes.

RESULTS

The endoscopic extent of disease was independently confirmed in 47 patients by US that yielded a 90% concordance with endoscopy (95% CI 0.82-0.96). Multiple regression analysis showed that US measurements with an independent predictive value of severity at endoscopy were increased bowel wall thickness (P < .0008), increased vascularity (P < .002), loss of haustra (P = .031), and loss of stratification of the bowel wall (P = .021). Each variable was assigned a value of 1 if present. The US score strongly correlated with clinical (r = 0.94) and endoscopic activity (r = 0.90) of disease (P < .0001).

CONCLUSIONS

Colonic US is a useful first line noninvasive tool to assess the extent and activity of disease in children with UC and to estimate the severity of a flare-up, prior to further invasive tests.

Bowel ultrasonography as an aid for diagnosis of intestinal acute graft-versus-host-disease after allogeneic haematopoietic stem cell transplantation

OBJECTIVE

Aim of our prospective study was to investigate accuracy of bowel ultrasonography in detecting gastrointestinal acute graft versus host disease (GVHD), when using clinical assessment as gold standard. In a subgroup of patients, bowel ultrasonography was compared with colonoscopy and histology in diagnosing of gastrointestinal acute GVHD.

METHODS

Fifty-two patients underwent allogeneic hematopoietic stem cell transplantation and developed gastrointestinal symptoms.

RESULTS

Clinical assessment lead to a diagnosis of gastrointestinal acute GVHD in 17/52 patients, no gastrointestinal acute GVHD was detected in 20/52 patients, while 15 patients were not able to complete the study. Bowel ultrasonography detected either bowel wall thickness of the ileum and the colon or dilation in 16/17 patients and showed 94% sensitivity (95% CI 0.69-0.99), 95% specificity (95% CI 0.73-0.99), and 94.5% accuracy. Colonoscopy was performed in 13/52 patients, showing gastrointestinal acute GVHD in 11/13. In these 11 patients, histology confirmed the diagnosis of gastrointestinal acute GVHD, and bowel ultrasonography detected findings compatible with gastrointestinal acute GVHD in all 11 patients, and was negative in the 2 patients with no gastrointestinal acute GVHD.

CONCLUSION

Bowel ultrasonography can be considered a valuable tool to add to clinical assessment for patients with suspected gastrointestinal acute GVHD for addressing a prompt and appropriate treatment.

Optimising monitoring in the management of Crohn's disease: a physician's perspective

Management of Crohn's disease has traditionally placed high value on subjective symptom assessment; however, it is increasingly appreciated that patient symptoms and objective parameters of inflammation can be disconnected. Therefore, strategies that objectively monitor inflammatory activity should be utilised throughout the disease course to optimise patient management. Initially, a thorough assessment of the severity, location and extent of disease is needed to ensure a correct diagnosis, identify any complications, help assess prognosis and select appropriate therapy. During follow-up, clinical decision-making should be driven by disease activity monitoring, with the aim of optimising treatment for tight disease control. However, few data exist to guide the choice of monitoring tools and the frequency of their use. Furthermore, adaption of monitoring strategies for symptomatic, asymptomatic and post-operative patients has not been well defined. The Annual excHangE on the ADvances in Inflammatory Bowel Disease (IBD Ahead) 2011 educational programme, which included approximately 600 gastroenterologists from 36 countries, has developed practice recommendations for the optimal monitoring of Crohn's disease based on evidence and/or expert opinion. These recommendations address the need to incorporate different modalities of disease assessment (symptom and endoscopic assessment, measurement of biomarkers of inflammatory activity and cross-sectional imaging) into robust monitoring. Furthermore, the importance of measuring and recording parameters in a standardised fashion to enable longitudinal evaluation of disease activity is highlighted.

Accuracy of small-intestine contrast ultrasonography, compared with computed tomography enteroclysis, in characterizing lesions in patients with Crohn's disease

BACKGROUND & AIMS

Small-intestine contrast ultrasonography (SICUS) is a radiation-free technique that can detect intestinal damage in patients with Crohn's disease (CD). We evaluated the diagnostic accuracy of SICUS in determining the site, extent, and complications of CD, compared with computed tomography (CT) enteroclysis as the standard.

METHODS

We performed a retrospective analysis of data from 59 patients with CD evaluated by SICUS and CT enteroclysis 3 months apart, between January 2007 and April 2012. We evaluated disease site (based on bowel wall thickness), extent of lesions, and presence of complications (stenosis, prestenotic dilation, abscess, or fistulas) using CT enteroclysis as the standard. Sensitivity, specificity, and diagnostic accuracy were calculated. We determined the correlations in maximum wall thickness and disease extent in the small bowel between results from SICUS and CT enteroclysis.

RESULTS

SICUS identified the site of small bowel CD with 98% sensitivity, 67% specificity, and 95% diagnostic accuracy; it identified the site of colon CD with 83% sensitivity, 97.5% specificity, and 93% diagnostic accuracy. Results from SICUS and CT enteroclysis correlated in determination of bowel wall thickness (rho, 0.79) and disease extent (rho, 0.89; P < .0001 for both). SICUS detected ileal stenosis with 95.5% sensitivity, 80% specificity, and 91.5% diagnostic accuracy, and prestenotic dilation with 87% sensitivity, 67% specificity, and 75% diagnostic accuracy. SICUS detected abscesses with 78% sensitivity, 100% specificity, and 97% diagnostic accuracy, and fistulas with 78.5% sensitivity, 95.5% specificity, and 91.5% diagnostic accuracy.

CONCLUSIONS

SICUS identified lesions and complications in patients with CD with high levels of sensitivity, specificity, and accuracy compared with CT enteroclysis. SICUS might be used as an imaging tool as part of a focused diagnostic examination of patients with CD.

Transmural healing evaluated by bowel sonography in patients with Crohn's disease on maintenance treatment with biologics

BACKGROUND

Both thiopurines and anti-tumor necrosis factor (TNF) α agents are effective for treating Crohn's disease (CD) as they can induce clinical remission (CR) and mucosal healing (MH) in most patients. Nevertheless, data on transmural healing (TH) induced by thiopurines and anti-TNF-α agents are still lacking. This study aimed to explore the rate of TH evaluated by bowel sonography in patients with CD treated with biologics and immunosuppressors and its correlation with CR and MH.

METHODS

We performed an observational longitudinal study evaluating TH, CR, and MH in all patients with CD attending our clinic who would complete 2 years of maintenance treatment with biologics or thiopurines. CR and MH were assessed in accordance with current literature, whereas TH was recorded using bowel sonography. All patients underwent endoscopy and bowel sonography before starting treatment and 2 years later.

RESULTS

The study included 66 patients with CD treated with biologics and 67 patients receiving thiopurines. Finally, TH was present in 17 patients on biologics and only 3 patients treated with thiopurines (25% versus 4%; P < 0.01; odds ratio = 6.2). CR was achieved in 37 patients on biologics and in 34 patients on thiopurines (59.7% versus 53%; P = not significant), whereas MH was more frequent in patients treated with anti-TNF-α agents even though without statistical significance (38% versus 25%; P = not significant).

CONCLUSIONS

TH can be achieved in approximately 25% of patients with CD treated with anti-TNF-α agents and significantly correlates with MH. Further studies are needed to define the potential role of TH as long-term prognostic factor.

Noninvasive diagnosis of small bowel Crohn's disease: direct comparison of bowel sonography and magnetic resonance enterography

BACKGROUND

The diagnosis of small bowel Crohn's disease (CD) is performed by ileocolonoscopy, whereas the assessment of its extension can be achieved by radiologic studies or, noninvasively, by magnetic resonance (MR) enterography and bowel sonography (BS). However, few comparative studies exist directly comparing the diagnostic accuracy of BS and MRI. The aim of this study was to evaluate the diagnostic accuracy of BS and MRI for the diagnosis of small bowel CD.

METHODS

We prospectively performed a noninferiority diagnostic study including 234 consecutive subjects with suspected small bowel CD. All patients underwent IC (used as gold standard for diagnosis), BS, and MR enterography performed in random order by physicians who were blinded about the results.

RESULTS

The diagnosis of small bowel CD was made in 120 of 249 subjects (48%). Sensitivity, specificity, positive predictive value, and negative predictive value for CD diagnosis were 94%, 97%, 97%, and 94% for BS and 96%, 94%, 94%, and 96% for MR enterography, respectively. BS was less accurate than MR enterography in defining CD extension (r = 0.69), whereas the concordance in terms of CD location between the 2 procedures was high (k = 0.81). Also, MRI showed a fair concordance with BS about strictures (k = 0.82) and abscesses (k = 0.88), with better detection of enteroenteric fistulas (k = 0.67).

CONCLUSIONS

BS and MR enterography are 2 accurate procedures for the diagnosis of small bowel CD, although MR seems to be more sensitive in defining its extension. BS could be used to select the patients for subsequent MRI examination.

Recent advances in understanding Crohn's disease

Crohn's disease is a chronic inflammatory bowel disorder resulting from an inappropriate innate and acquired immune response to commensal microorganisms in genetically susceptible individuals. This disease has a fluctuating course, with alternating periods of remission and relapses, and it is characterized by a remarkable clinical heterogeneity; it may be complicated by perianal fistulas, abscesses, and intestinal strictures leading to obstructions, besides several systemic manifestations. However, a complete resolution of the disease is currently not possible, yet Crohn's disease can be managed with established and novel therapies, which achieve long-term remission and acceptable quality of life. This review is focused on novel advances in basic and clinical aspects of Crohn's disease, although it also deals with new trends in diagnosis and treatment.

Development of a numerical index quantitating small bowel damage as detected by ultrasonography in Crohn's disease

Small intestine contrast ultrasonography (SICUS) has emerged as a valuable tool in the detection of intestinal damage in Crohn's disease (CD). Our aim was to develop a numerical index quantitating small bowel damage as detected by SICUS in patients with an established diagnosis of CD. One hundred and ten patients with ileal or ileocolonic CD were prospectively enrolled and followed up for one year. Disease activity was assessed by CDAI and CRP levels. Study variables included bowel wall thickness, lumen diameter, lesion length and number of lesion site. Fistula, mesenteric adipose tissue alteration, abscess and lymphnodes were also considered. Bowel segments were considered as a hollow cylinder. Standardized variations of variables were combined into a statistical and mathematical model to create an algorithm scoring an index value ranging from 0 to 200. Index was subdivided into a severity scale with 5 classes from the lower (A) to the higher score (E). Median lesion index value was significantly higher (p<0.005) in patients with a CDAI>150 and in patients with CRP>5 mg/l (p=0.003). Patients classified in class E and D at SICUS underwent surgery within one year follow up more frequently than those in class C, B and A (p<0.0001). We propose a new index for assessment of small bowel lesions in CD (SLIC: sonographic lesion index for CD) developed by using SICUS. This index may turn ultrasonography in CD from a descriptive qualitative assessment to a quantitative numerical index suitable for comparison studies.

A new look at Crohn's disease: novel imaging techniques

PURPOSE OF REVIEW

Imaging the gut provides information on Crohn's disease activity, identifies complications and provides insight into patient symptoms. Imaging can help direct therapy and can predict important patient outcomes. In a rapidly changing, technology-driven field, new imaging applications add novel insights that we are only beginning to appreciate. The purpose of this review is to highlight recent advances in imaging as they are applied to the assessment of patients with Crohn's disease.

RECENT FINDINGS

In the past year, key literature describing cross-sectional imaging techniques, including computed tomography (CT) based imaging, specifically CT enterography (CTE) and magnetic resonance enterography (MRE), transcutaneous ultrasound, and PET-based imaging, has emerged in the field of inflammatory bowel disease. MRI sequences that have been recently applied to Crohn's disease assessment, including diffusion-weighted imaging (DWI) and magnetization transfer imaging (MTI), add important new insights. These new data highlight the current status of available imaging modalities and provide a glimpse into the future of our practice.

SUMMARY

CTE and MRE are our new standard imaging modalities for small bowel Crohn's disease. PET scanning is promising but currently only used routinely in centers with a strong research presence in this area. Ultrasound is emerging as a useful, potentially less costly, radiation-free technique. New MRI sequences offer future promise for effectively monitoring the natural history of Crohn's disease.

Ultrasound of the small bowel in Crohn's disease

Several radiological and endoscopic techniques are now available for the study of inflammatory bowel diseases. In everyday practice, the choice of the technique to be used depends upon its availability and a careful evaluation of diagnostic accuracy, clinical usefulness, safety, and cost. The recent development of innovative and noninvasive imaging techniques has led to a new and exciting area in the exploration of the gastrointestinal tract, especially in Crohn's disease patients by using ultrasound with oral or intravenous contrast.

Results of the 2nd part Scientific Workshop of the ECCO. II: Measures and markers of prediction to achieve, detect, and monitor intestinal healing in inflammatory bowel disease

The healing of the intestine is becoming an important objective in the management of inflammatory bowel diseases. It is associated with improved disease outcome. Therefore the assessment of this healing both in clinical studies and routine practice is a key issue. Endoscopy for the colon and terminal ileum and computerized tomography or magnetic resonance imaging for the small bowel are the most direct ways to evaluate intestinal healing. However, there are many unsolved questions about the definition and the precise assessment of intestinal healing using these endoscopic and imaging techniques. Furthermore, these are relatively invasive and expensive procedures that may be inadequate for regular patients' monitoring. Therefore, biomarkers such as C-reactive protein and fecal calprotectin have been proposed as surrogate markers for intestinal healing. Nevertheless, the sensitivity and specificity of these markers for the prediction of healing may be insufficient for routine practice. New stool, blood or intestinal biomarkers are currently studied and may improve our ability to monitor intestinal healing in the future.

Ultrasound elasticity imaging for detecting intestinal fibrosis and inflammation in rats and humans with Crohn's disease

BACKGROUND

Intestinal fibrosis causes many complications of Crohn's disease (CD). Available biomarkers and imaging modalities lack sufficient accuracy to distinguish intestinal inflammation from fibrosis. Transcutaneous ultrasound elasticity imaging (UEI) is a promising, noninvasive approach for measuring tissue mechanical properties. We hypothesized that UEI could differentiate inflammatory from fibrotic bowel wall changes in both animal models of colitis and humans with CD.

METHODS

Female Lewis rats underwent weekly trinitrobenzene sulfonic acid enemas yielding models of acute inflammatory colitis (n = 5) and chronic intestinal fibrosis (n = 6). UEI scanning used a novel speckle-tracking algorithm to estimate tissue strain. Resected bowel segments were evaluated for evidence of inflammation and fibrosis. Seven consecutive patients with stenotic CD were studied with UEI and their resected stenotic and normal bowel segments were evaluated by ex vivo elastometry and histopathology.

RESULTS

Transcutaneous UEI normalized strain was able to differentiate acutely inflamed (-2.07) versus chronic fibrotic (-1.10) colon in rat models of inflammatory bowel disease (IBD; P = .037). Transcutaneous UEI normalized strain also differentiated stenotic (-0.87) versus adjacent normal small bowel (-1.99) in human CD (P = .0008), and this measurement also correlated well with ex vivo elastometry (r = -0.81).

CONCLUSIONS

UEI can differentiate inflammatory from fibrotic intestine in rat models of IBD and can differentiate between fibrotic and unaffected intestine in a pilot study in humans with CD. UEI represents a novel technology with potential to become a new objective measure of progression of intestinal fibrosis. Prospective clinical studies in CD are needed.

Ultrasonographic assessment of colonic wall in moderate-severe ulcerative colitis: comparison with endoscopic findings

BACKGROUND

Bowel ultrasound has been shown to be a useful tool to evaluate patients with inflammatory bowel disease, especially Crohn's disease. However, such data are still scarce in ulcerative colitis patients.

AIMS

To establish the value of bowel ultrasound in moderate to severe ulcerative colitis patients, and compare these data with endoscopic findings.

PATIENTS AND METHODS

Endoscopic, ultrasound and C-reactive protein data from 51 patients with moderate to severe ulcerative colitis observed during a 3-year period were retrospectively obtained and analysed.

RESULTS

All patients displayed pathological thickness (>4 mm) of the colon wall. This value strongly correlated with C-reactive protein values (p=0.0001) and the endoscopic score (p<0.0001). Also, a strong correlation (p<0.0001) was found between CRP values and endoscopic score.

CONCLUSIONS

Bowel ultrasound, in expert hands, may represent a useful adjunctive (or first line) tool for the evaluation of patients with moderate to severe ulcerative colitis.

Diagnostics in inflammatory bowel disease: Ultrasound

Diagnosis of chronic inflammatory bowel diseases (IBD) is based on a combination of clinical symptoms, laboratory tests and imaging data. Imaging of the morphological characteristics of IBD includes the assessment of mucosal alterations, transmural involvement and extraintestinal manifestations. No single imaging technique serves as a diagnostic gold standard to encompass all disease manifestations. Ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) allow cross-sectional imaging of the transmural alterations and extraintestinal manifestations. While in the USA the technique of choice is CT, in Europe the focus is more on MRI and ultrasound (US). Most patients with chronic IBD are diagnosed at a young age. After baseline diagnosis many of these young patients have to undergo repetitive imaging procedures during the variable clinical course of the disease, characterized by alternate periods of remission and active disease, and in monitoring the response to treatment. US has the advantage of being noninvasive, less costly, and easily repeatable, and thus can be very useful in following up patients with IBD. In addition, rising concern about radiation exposure in young adults indicates the demand for radiation-sparing techniques like US and MRI. This article focuses on the current clinical practice of US in IBD, describing the current technologies used in transabdominal intestinal US and the characteristic sonographic findings in Crohn´s disease and ulcerative colitis.

Diagnostic value and clinical utility of contrast enhanced ultrasound in intestinal diseases

Contrast enhanced ultrasound (CEUS) has recently gained increasing attention as it clearly improves the visualisation of perfusion in various tissues. The development of second generation contrast enhancing agents used in low-mechanical-index harmonic ultrasound has enabled real-time assessment of the microvascular circulation and quantification of bowel wall vascularity. For this review Medline was searched for clinical studies using CEUS to investigate the gastrointestinal tract. Many studies demonstrate that acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed semi-quantitatively using contrast enhanced ultrasound analyzing time intensity curves. In contrast, ischemia is characterized by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by CEUS. CEUS at a preliminary stage has been described as clinically important in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease. CEUS facilitates the detection of disease extent and activity, and its luminal and extraluminal complications.

Are colonoscopy and bowel ultrasound useful for assessing response to short-term therapy and predicting disease outcome of moderate-to-severe forms of ulcerative colitis?: a prospective study

OBJECTIVES

Mucosal healing has been proposed as an important sign of the efficacy of medical treatment of inflammatory bowel disease; however, direct evidence in ulcerative colitis (UC) is scarce. We evaluated the usefulness of colonoscopy and bowel ultrasound (US) as indexes of response to short-term therapy and as predictors of subsequent outcome in UC.

METHODS

A total of 83 patients with moderate-to-severe UC were recruited; endoscopic and US severity was graded 0-3 at entry according to validated scores. Of the recruited patients, 74, who were clinically responsive to steroids, were followed up with repeated colonoscopy and bowel US at 3, 9, and 15 months from recruitment. Concordance between clinical, endoscopic, and US scores at various visits was determined by kappa statistics. Multiple unconditional logistic regression models were used to assess the predictivity of clinical, endoscopic, and US scores measured at 3 and 9 months on the development of endoscopic UC relapse within 15 months.

RESULTS

A variable concordance was found over time between endoscopic and clinical score (weighted kappa between 0.38 and 0.95), with high and consistent concordance between endoscopic and US scores (weighted kappa between 0.76 and 0.90). On logistic regression analysis, moderate-to-severe endoscopic and US scores at 3 months were associated with a high risk of endoscopic activity at 15 months (odds ratio (OR): 5.2; 95% confidence interval (CI): 1.6-17.6 and OR: 9.1; 95% CI: 2.5-33.5, respectively).

CONCLUSIONS

Bowel US may be used as a surrogate of colonoscopy in assessing the short-term response of severe forms of UC to therapy. Both US score and endoscopic score after 3 months of steroid therapy predict outcome of disease at 15 months.

Ultrasound of the bowel in children: how we do it

Advances in US like high-resolution transducers, harmonic imaging and panoramic modality have overcome some of the obstacles for sonography of the small and large bowel that existed in the past. In a number of centers, bowel US is an established routine method both in adults in children. Bowel US has the distinct advantages of being widely available, relatively cheap, free of radiation and easy to perform. In addition, US of the bowel demonstrates both mural and extramural pathological changes. Patients with inflammatory bowel disease have frequent imaging studies due to disease recurrences and need of follow-up after treatment. Thus this group of pediatric patients benefits most from an optimized and standardized bowel US. This review provides a comprehensive step-by-step approach how to perform US of the bowel in children with emphasis on imaging inflammatory bowel changes. It is meant to serve like a recipe and facilitate the routine performance of US of the bowel in children.

Abdominal bowel ultrasound can predict the risk of surgery in Crohn's disease: proposal of an ultrasonographic score

OBJECTIVE

Abdominal bowel ultrasound (US) is widely used in the management of Crohn's disease (CD). The aim of this study was to evaluate the prognostic role of bowel-wall US morphology on the short-term risk of surgery.

MATERIAL AND METHODS

The 147 CD patients recruited in a case-control study comprised 49 cases operated on within 30 days after US examination and 98 matched non-operated controls. Clinical and US characteristics were analysed. Bowel-wall thickness was recorded, bowel-wall patterns were grouped into five types, but for final analysis they were grouped as "preserved" or "disrupted stratification".

RESULTS

Wall thickness and US patterns were significantly different between cases and controls (p<0.0001). A wall thickness >4.5 mm was observed in 45/49 cases and 47/98 controls (OR = 12.21), while "disrupted stratification" was observed in 34/49 cases and 12/98 controls (OR = 16.24). Among the clinical and US characteristics recorded, only 4 US variables were independently associated with surgery (pattern, thickness, presence of fistulae/abscesses and stenoses) and considered for the US score=(2.5*US pattern)+(1.5*Bowel thickness)+(3*Presence of fistulae/abscesses)+(1.5*Presence of stenoses). Based on this score, up to 84% of patients were correctly classified according to actual status (operated/non-operated).

CONCLUSIONS

Although it needs further prospective validation, the score we propose seems to be a reliable prognostic marker for the short-term risk of surgery in CD. In particular, the score points out those patients with an impending risk of surgery who need careful and frequent control in order to decide on the right time for surgery.